Here are some things I have done. I already found the volume since the other part of the question said to use the method of discs/washers. It is 54.0633 cubic units (correct answer).
I found by trial and error that (since this is an online assignment) that a= 9/sqrt(82) and c =9 .
What do I do? Why should there be two integrals, I don't understand.
I have tried the following.
y = 9^x becomes x = lny/ln9
h = lny/ln9
r = y
So I got integral from 9/sqrt(82) to 9 of
But that's just one integral and perhaps even incorrect. Please show me what to do.